process and device for the operation of a blast furnace with recycled top gas and rige nerato

摘要

1344714 Blast furnaces NIPPON KOKAN KK 25 June 1971 [6 July 1970] 29839/71 Heading F4B [Also in Division C7] In operating a blast furnace 1, gas extracted peripherally at 18 above the charge surface 17 and at a temperature up to 700‹ C. is recirculated to a point above the softening and melting zone 15 above the tuyeres 8 via a line 10, fan 3, gas regenerator 4 and line 14, further gas extracted from the middle of the charge passing off by a line 9 and being divided, part 9a being used to fire a hot blast store 2, part 9b to fire the regenerator 4 and part 9c for other external uses. A line 11 supplies methane to mix with the recirculated top gas, the gas regenerator converting any H 2 O or CO 2 into H 2 or CO. The recycled gas may be extracted through pipes extending vertically in the furnace near the stack wall and terminating just above the charge surface or through pipes with mouths within the upper part of the charge. Owing to its extraction and return near the stack wall the recycled gas contains less nitrogen than the unrecycled gas.